Hey just pointing out the current rules as presented state that "This involves simply making a new investment of vis (of an amount based on your current age) but no significant investment in time."
The problem is that you are limited to 2*MT for vis expenditures. I think I remember somewhere that this got ruled that the MT is only for creation of the original ritual and any recreation uses Creo+Corpus+Vim for the limit.
That probably needs to get into DE. If the MT limit is applied, longevity rituals become questionable for magi over about 50 (needs 1 pawn per 5 years of age, so age 50 requires a MT score of 5 and things only get worse from there).
I don't see, where that limit is stated for just taking some short time to "repeat the focus" of an existing Longevity Ritual. Repeating the focus clearly is no Laboratory Activity.
But the 2*MT limit on vis certainly applies, if you reinvent a Longevity Ritual: many old magi just for this reason might require the help of a true lab rat.
The amount of raw vis that a magus may use in a single season is limited to twice his Magic Theory score. The magus cannot successfully integrate any more vis into a single project. In many sagas, vis will be rare enough that this limit will not come into play.
Vis Limit: Magic Theory x 2 pawns per season
and
Every magus has a unique Longevity Ritual, though it is possible for a magus to create a Longevity Ritual for another. Indeed, many young magi hire older magi to devise their Longevity Rituals, as the older magus's higher Lab Total makes the ritual much more effective. It is most common for a magus to pay his parens for this, and in some parts of the Order this is almost an expected custom.
Longevity Ritual: +1 bonus for every five points or fraction of Creo Corpus Lab Total
Longevity Ritual Vis Cost: 1 pawn for every five years of age (rounded up)
Normally, only Creo, Corpus, and Vim vis may be used in a Longevity Ritual. However, a Longevity Ritual is a very personal creation, and as such, it is uniquely tied to your magical abilities. You may, with the approval of the troupe or storyguide, substitute any type of vis that your magical talents are strongly associated with.
A Longevity Ritual's effect lasts until you suffer an aging crisis (see "Aging" on page @@). After this, the ritual loses its effectiveness and the focus must be repeated. You can invent a new ritual (following the normal rules for doing so), or perform the ritual from the old ritual again. This involves simply making a new investment of vis (of an amount based on your current age) but no significant investment in time. You must have the Laboratory Text (see page @@) from the original ritual to do this, and this is the only benefit from a Longevity Ritual's Laboratory Text. If your Longevity Ritual fails and you make aging rolls before you create a new one, you suffer the full effects of your age. You do not gain back any Aging Points or Decrepitude Points that you suffered when you were not under the effects of a ritual when you do finally perform a new ritual.
I'm not seeing it, and if I'm not maybe it should get a line.
The new investment of time and vis is not a Lab Project. And different applications of vis are limited in different ways, like by the scores of the Arts corresponding to used vis (ArM5 p.82).
Does that help?
That it is not a lab project is kind of irrelevant. (And I am not so sure it isn't)
The important thing is that it is not a seasonal project - those are the ones with the 2xMT limit.
So the resolution is that:
'Researching / devising a longevity ritual for a target' IS a seasonal / laboratory activity; it generates a lab text, uses the standard lab totals, etc -- but it is separate from actually performing the ritual, and uses no Vis.
'Using / casting / performing the Longevity ritual' is NOT a seasonal activity; and is restricted by the art scores & etc -- and this is where the Vis in question is actually consumed.
I wouldn't care about this distinguo one way or the other, were there not the other quote by @SteveD above:
So if there were - contrary to my perception - some non-seasonal lab projects, their use of vis would be limited by this quote. But the quote does not postulate the existence of such projects.
Faerie Magic and Chthonic Magic can increase the amount of vis you can use, if it is all faerie vis or infernal vis.
There are also virtues that improve your MT (Puissant Magic Theory, for example), and virtues that decrease the amount of vis required for various things. (Verditius Magic, Celestial Magic, and Imbued with the Spirit of (Form) are some of them).
I read from someone - IIRC it was Timothy Ferguson on his blog - that the longevity ritual could be (optionally) treated as a mystery ritual that is universally known but not fully integrated into Hermetic magic.
Back to my opinion, don't blame anyone else: As a mystery ritual, it can be safely (with the approval of the troupe) treated as a special case and the concerns about vis usage can be hand waved away and otherwise ignored. If a researcher realized that it was a mystery ritual and successfully integrated the ritual into Hermetic magic, improvement would be much easier to effect.
As I'm considering the implications of this- I think it is safe to assume that MT maxes out at 16 (enough to write a level 8 summae), at least for background magi, and that is rare (i.e. expensive), but would allow for the formulation of longevity rituals for those up to age 80 (before other cost reducing options), after which you are largely stuck with whatever you have for your longevity ritual. On the other hand older magi will require more vis to renew their ritual when it fails, so there are likely to be a lot of older magi with a lot if investment in corpus and creo (or whatever other art happens to be in their individualized ritual)
Actually, that would be "up to age 160".
The number of pawns used in a seasonal activity can be up to Magic Theory score times two.
That would be some 130-140 years after gauntlet, which roughly coincides with the time "standard" magi start slipping into Final Twilight, so it kind of makes sense.
A Magic Theory score of 16 should be extremely rare. Perhaps one or two magi throughout the history of the Order have got there.
But a score of 12 (including Puissant) is quite achievable, and would let you use up to 2x12=24 pawns of vis per season. Enough to make a Longevity Ritual for a 120 years old magus. Various virtues can increase that a bit.
I would not be so certain. A score of 16 in an Ability is 680xp. To put that into perspective, 680xp in an Art gives you a score of 36(14), which I'd qualify as impressive, but not something that was only achieved by "perhaps one or two magi throughout the history of the Order".
I'd say that there are probably several magi with this score in Magic Theory at any one time, at least one of them a longevity specialist. That's particularly true because Magic Theory is so important to longevity specialists, due to the vis limit. A magus who's 105-110 years out of his gauntlet, and who's put just 6xp/year in Magic Theory (say, 3 exposure xp from an average of 1.5 seasons/year in the lab, and 3 from a good, but not really exceptional book of Quality 10 or so once every 3-4 years) has a MT score of 16 even without any special Virtue like an Affinity.
I had a bonisagus in one game that had a score of about 12 in MT after just a couple of years. They were very strong in research, but I found I was inventing spells to pursue breakthroughs that she wasn't actually able to cast because they were to high above her sta+arts. So its not likely for adventuring magi, but for a lab rat it is definitely achievable.
She did sort of "cheat" by educating mundanes with high com scores in magic theory then having them write tractatus, read each other's tractatus, then write more tractatus... that she also read ro boost her ability. On the other hand if there is one ability that is common to all magi it would be MT, meaning any competent author should be able to write at least one tractatus and there should always be demand for more. When you are looking at 11-13 xp/season (especially for a young bonisagus who is going to be using that score for decades) getting to 16 really isn't that difficult. The bigger part is finding the motivation to study from level 13-16, but as pointed out that could be exposure.
I've added a clarification that the spell limit (Arts) applies when re-performing your own ritual, not just one for someone else.
I'm not sure that there is a problem with the requirement for initial invention. It's only a problem for magi who suddenly need a ritual with a much higher bonus than the existing one, and even then it may not be a problem in practice — any magus with the Lab Total to make a useful Longevity Ritual is likely to have a very high Magic Theory, due to being a lab work specialist. I am not convinced that we need, or want, errata to address those cases.